Final answer:
Doubling the money spent on prevention from £2000 to £4000 per week would result in a new scrap rate of 1%.
Step-by-step explanation:
To estimate the new scrap rate percentage, we can use the fact that each 1% increase in scrap represents £4000 per week. Doubling the money spent on prevention from £2000 to £4000 per week means that the prevention cost will increase to £4000 per week. Now, we need to find the scrap percentage that corresponds to this new prevention cost by dividing the new prevention cost (£4000) by the cost per 1% increase in scrap (£4000). This gives us a new scrap rate of 1%.